Possible enhancement of the
in the two-Higgs-doublet model
Institut für Theoretische Physik der Universität Karlsruhe,
76128 Karlsruhe, Germany
Received: 26 November 1999 / Revised version: 7 July 2000 /
Published online: 8 September 2000 - © Springer-Verlag 2000
The production process of the charged Higgs boson associated with a W boson at electron-positron colliders is discussed in the two-Higgs-doublet model (2HDM) and in the minimal supersymmetric standard model (MSSM). The process is induced at one-loop level in these models. We examine how much the cross section can be enhanced by quark- and Higgs-loop effects. In the non-SUSY 2HDM, in addition to large top-bottom (t-b) loop effects for small ( ), the Higgs-loop diagrams can contribute to the cross section to some extent for moderate values. For larger ( ), such an enhancement by the Higgs non-decoupling effects is bounded by the requirement of the validity of perturbation theory. In the MSSM with heavy superpartner particles, only the t-b loops enhance the cross section while Higgs-loop effects are very small.
Copyright Società Italiana di Fisica, Springer-Verlag 2000